Answer:
<h2>Focal length</h2>
Explanation:
The Focal length of a lens is the distance from the center of the lens to
its principal focus.
Answer:
s₁ = 0.022 m
Explanation:
From the law of conservation of momentum:

where,
m₁ = mass of hockey player = 97 kg
m₂ = mass of puck = 0.15 kg
u₁ = u₂ = initial velocities of puck and player = 0 m/s
v₁ = velocity of player after collision = ?
v₂ = velocity of puck after hitting = 48 m/s
Therefore,

negative sign here shows the opposite direction.
Now, we calculate the time taken by puck to move 14.5 m:

Now, the distance covered by the player in this time will be:

<u>s₁ = 0.022 m</u>
<span>So the question is how does heat prefer to remain and to unscramble the letters ONMFRIU. The unscrambled letters mean: UNIFORM. The heat likes to remain uniform because thermodynamic systems always tend to reach thermal equilybrium after some period of time that is specific for each system. </span>
Answer:
Time period of oscillations is 0.62 s
Explanation:
Due to suspension of weight the change in the length of the spring is given as


now we know that spring is stretched due to its weight so at equilibrium the force due to weight is counter balanced by the spring force



Now the period of oscillation of spring is given as

Now plug in all values in it


Answer:
120,000J
Corrected question;
In one hour, coal supplies 500 000 J of energy. The wasted energy amounts to 380 000 J. How much useful energy is produced in one hour?
Explanation:
Given;
Total energy Et = 500,000 J
Wasted Energy Ew = 380,000J
The amount useful energy is the amount of energy that is available for supply.
This can be derived by subtracting the wasted energy from the total energy.
Useful energy = Total Energy - wasted energy
Eu = Et - Ew
Substituting the given values;
Eu = 500,000J - 380,000
Eu = 120,000 J
The amount of useful energy produced in one hour is 120,000 J